An organic light-emitting device includes an anode, a cathode, and a thin film that contains a fluorescent organic compound and is interposed between the anode and the cathode. When electrons and holes are injected from the respective electrodes, excitons of the fluorescent compound are generated and the light emitted by the excitons returning to their ground state is utilized by the device.
Organic light-emitting devices are also called organic electroluminescence devices or organic EL devices.
Recent advancement of organic light-emitting devices has been remarkable and suggested possibilities of applying the devices to a wider range of usages. This is because they can achieve high luminance with low voltage, a wider range of emission wavelengths, rapid response, and reduction in thickness and weight.
Development of novel compounds has been actively pursued to the present because creation of novel compounds is critical in making high-performance organic light-emitting devices. For example, Patent Citations 1 to 4 below describe examples of materials used for emission layers.    Patent Citation 1    Japanese Patent Laid-Open No. 1-289907    Patent Citation 2    Japanese Patent Laid-Open No. 2-247278    Patent Citation 3    Japanese Patent Laid-Open No. 8-113576    Patent Citation 4    Japanese Patent Laid-Open No. 11-12205